HAWAI'I KAI — Waves as high as 10 feet curled and crashed onto the shore along O'ahu's east shore yesterday, making it a busy day for lifeguards and a boon for surfers.

Sandy Beach looked like a weekend day as tourists and local residents did drive-bys, cars double-parked and visitors sat on the beach in awe.

High surf closed Makapu'u Beach to swimmers and generated waves of 5 feet inside Hanauma Bay. In all, county lifeguards issued nearly 1,000 warnings to swimmers and surfers yesterday from Makapu'u to Hanauma Bay. In addition, lifeguards assisted 13 people out of the heavy surf and made six rescues, said Bryan Cheplic, city Emergency Services Department spokesman.

The surf kept a Young Brothers barge from docking at Kahului Harbor on Maui. The ship will try again today after it attempted to enter the harbor twice yesterday.

In Hilo, Bayfront Highway was closed in both directions near Hilo Bay from Waiänuenue Avenue to Pauahi Street because of high surf.

The National Weather Service issued a high surf warning through 6 p.m. today for east-facing shores of O'ahu and Kaua'i. Surf is expected to be 12 to 18 feet and will gradually decrease, but will remain elevated through the weekend, according to the weather service.

"It's being caused by a play between a strong high pressure to the north and a low pressure to the west," said Norman Hui, a weather service forecaster. "This is not your normal surf. The surf probably peaked as we speak, but it's still going to be big."

The high surf prompted Kaua'i officials to issue a warning to beachgoers not to go near wet sand or in the water at all north or east side beaches from Hä'ena, Hanalei and Ke'alia where surf was reported at 15 to 25 feet.

On O'ahu, lifeguards closed Makapu'u to swimmers, but the beach park remained open. An orange sign that said "Beach closed Hazardous conditions No swimming" and yellow caution tape greeted visitors to the beach park.

"We had heard the surf was big," said Chicago visitor Delmer Reed. "We swam here last year, but right now, I'd say no thank you. I'm going to respect the surf."

At Sandy Beach, only the most experienced surfers braved the surf yesterday. A lifeguard cruised outside the breaking waves on a personal watercraft , said lifeguard Lt. J.R. Sloane.

"It's very rare that we get a swell like this out of the northeast direction," Sloane said. "It's really busy today. We're trying to keep as many people out of the water as possible.

"We've got it covered pretty well."

Breanna Mann, an Alaskan visitor, decided yesterday to go to another beach where the waves were just a tad tamer.

"We're not used to these kinds of waves," Mann said. "We don't need to drown on our vacation. I think we'll just sit on the sand and take pictures."

From the top of Makapu'u, Jerico Asing of Papakolea surveyed the empty beach below and the high surf kicked up a spray of sea salt haze.

"This doesn't look too rough," Asing said. "I don't know why it's closed."

Holding his surfboard, Steve Chang, an 'Äina Haina resident, said the surf was good off Flat Island to the left of Makapu'u at a break called Suicides.

"It was fun," Chang said. "It's dangerous if you don't know what you're doing. I think it is smart to close Makapu'u beach because plenty of tourists come to swim out here.

"If I don't have to work tomorrow, I'll be back here."